The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines draw air into an intake manifold through an inlet system that may be regulated by a throttle. The air in the intake manifold may be distributed to a plurality of cylinders and combined with fuel from fuel injectors to create an air/fuel (A/F) mixture. The A/F mixture may be combusted within the cylinders to drive pistons which rotatably turn a crankshaft generating drive torque. The drive torque may be transferred to a driveline (e.g., wheels) of a vehicle by a transmission.
The fuel injectors may operate in a plurality of modes. More specifically, the fuel injectors may operate in a normal fuel injection mode or a split fuel injection mode. The split fuel injection mode may include multiple (e.g., first and second) fuel injections during each combustion cycle. The first injection may be referred to as a “pilot injection” and may include a relatively small quantity of fuel. The pilot injection may increase a temperature within the cylinders thereby improving combustion of the subsequent second injection. The second fuel injection, on the other hand, may be referred to as a “main injection” and may include a relatively large quantity of fuel. In other words, the main injection may include a remainder of a desired quantity of fuel to be injected during the combustion cycle (e.g., main=desired−pilot).